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Why Your Computer Is Slow And How To Fix It ASAP

Ronald Bushnell

man using a slow computer

A slow computer can really make your life difficult. Not only will you be unable to get work done on time, but you will also get frustrated and angry. The combination of a slow computer and a less than optimal state of mind is not a recipe for success.

Knowing how to fix your slow computer will not only help you solve your current problem. It will also enable you to take proactive action and ensure that your computer performs optimally at all times. 

Read on to understand what makes your computer slow and what you can do to fix it ASAP.  

What Makes Your Computer Slow?

The main reasons for a slow computer are

  • Insufficient or overloaded resources
  • Viruses, malware, and other types of malicious software
  • Network-related issues
  • Outdated hardware

Therefore, it is important to first spend some time investigating the symptoms, and only then can you find and fix the root cause to solve your problem. 

Restart Your Computer

Before reading further, one thing you can try is to restart your computer. While this may seem simplistic, restarting a computer frees up resources that may be causing it to operate slowly. 

However, if rebooting only provides a temporary respite, then read on!

Insufficient or Overloaded Resources 

One of the main reasons for a slow computer is insufficient or overloaded resources.

Let’s consider the analogy of a car: the main resources of a car are its engine, fuel, and carrying capacity. If a car has a small engine, it may work well on roads but struggle on difficult terrains such as hills and mountains. The car will stop running if the fuel runs out. And the car will run slowly if it gets overloaded with passengers and/or luggage. 

For computers, the main resources are the central processing unit or CPU, Random Access Memory or RAM, and storage/hard drive capacity. If any of these resources are insufficient or overloaded, then computer performance and speed will suffer.

High CPU Load

The CPU is the brain of your computer. Its function is similar to a car’s engine.

The CPU executes software instructions and provides the processing power the computer needs to do its work. 

If your computer runs slowly, the first thing that you should do is check the CPU utilization: 

  • On Windows, you can check CPU utilization via the Performance tab in Task Manager
  • On Mac, you can check CPU utilization in Activity Monitor.

The CPU load varies on a continuous basis. This is normal. However, continuously high CPU load (>90%) is a clear indicator that a software application or process is consuming excessive CPU resources. Not only will this cause your computer to run slowly, but it will also cause the CPU temperature to rise. At times your computer will shut down abruptly to prevent your CPU from overheating. 

This is similar to what happens with a car engine that runs at high RPM: it’s ok for a few minutes, but any longer than that can cause your engine to overheat and, in extreme cases, get seriously damaged.

How to Reduce CPU Load

  • Close CPU-intensive programs: If you are running several programs at the same time, then one thing you can do is close the programs that you don’t need. Graphics and gaming platforms, for example, are resource-hungry. And you can pinpoint the exact program/process that is using a high percentage of CPU resources by using built-in diagnostic tools that are available on your computer’s operating system. (Windows/Mac)
  • Disable start-up programs: Some programs on your computer are configured to start automatically whenever your computer boots up. All running programs consume computer resources, including the CPU. So one thing that you can do to reduce CPU load is to look at the startup programs and disable the ones that you don’t need. (Windows/Mac
  • Check for incomplete software updates: Updates for your operating system and other programs also utilize the CPU. And you may not notice because these processes operate in the background. 
  • Remove malicious software: Viruses, malware, spyware, and other malicious software can cause CPU utilization to shoot up to 100%. If other methods don’t solve the problem, then you should scan for viruses and malicious software, and if found, remove them from your computer. 
  • Upgrade your CPU: If you have a computer with an old CPU, and you want to run all types of new software on it, then the only option is to upgrade your computer/CPU. This is because modern software is more resource-hungry compared to older software. And no manner of troubleshooting can make your old computer run fast with modern software.

High RAM Utilization

Random Access Memory (RAM) is temporary storage on your computer. The computer copies programs and data that you use from the hard drive to RAM. This is because RAM is much, much faster than the hard drive. Copying programs and data to RAM makes the process of working on computers much faster. 

If the RAM gets fully utilized, then your computer will slow down because your computer will start using space on your hard disk, which is much slower to simulate RAM. 

To check RAM utilization:

  • On Windows, you can check RAM utilization via the Performance tab in Task Manager.
  • On MAC, you can check RAM utilization in Activity Monitor.

RAM utilization varies during computer use. However, continuously high RAM utilization (>90%) points towards insufficient RAM.

How to Reduce RAM Utilization

The steps listed above for reducing CPU load are also valid for reducing RAM utilization. This is because, in general, programs and processes that consume CPU resources also consume RAM. In addition, you can:

  • Close unnecessary browser tabs: Each browser tab that you open consumes a certain amount of RAM. 
  • Delete unused browser extensions: Browser extensions also consume RAM, so you can delete unused browser extensions to free some up.
  • Try a different browser: Browsers manage RAM differently. If you note that your browser runs slowly, you can try a different browser.
  • Remove unnecessary software: Go through the list of installed applications on your computer and uninstall the ones you no longer need.
  • Update software to the latest versions:  Outdated software often requires more RAM. Updating your software to the latest versions can reduce overall RAM utilization.
  • Disable background apps: To free up RAM, you can disable unneeded background apps. (Windows/Mac
  • Choose a simpler desktop theme: Visual effects and fancy desktop themes look nice but can consume RAM and slow down your PC. Choosing a simple desktop theme can free up RAM and help to improve computer performance. 
  • Add RAM: If RAM utilization does not reduce sufficiently even after trying all the above methods, then it’s time for you to increase the amount of RAM on your computer.   

Insufficient Free Space on your HDD

The hard drive or hard disk drive (HDD) provides fixed storage on your computer. When the RAM becomes full, your computer uses a portion of your hard drive as virtual RAM. If your hard drive is out of space, the computer will not be able to create this virtual RAM, and the computer may slow down drastically.

How to Free Up Space on your Hard Drive

To free up space on your hard drive, you can

  • Remove unnecessary software applications
  • Remove unnecessary files and photos
  • Transfer data from your hard drive to cloud storage
  • Empty the recycle bin on Windows  / Trash on Mac
  • Clear temporary files (Windows/Mac)
  • Upgrade your HDD: If, despite all the recommended space-clearing measures, you keep running out of space on your hard drive, then it’s time to either add another hard drive to your computer or upgrade to a hard drive with more capacity. You can also switch over to a solid-state drive (SDD), which is faster than an HDD. SSDs are more expensive but will improve the overall performance of your computer. Please see the following table for a comparison between HDD and SDD speeds. 
DeviceRead SpeedWrite Speed
Seagate Barracuda HDD 1 TB210 MB/s210 MB/s
Samsung 970 EVO Plus SSD 1 TBUp to 3500 MB/sUp to 3330 MB/s

Network-Related Issues

If you find that your computer becomes slow only when you access the Internet or connect to your corporate Intranet, then it’s time to look at network-related issues.

  • Unstable WiFi: A slow or unreliable WiFi connection will affect data throughput, and the computer will become unresponsive and sluggish. First, check the WiFi link speed (Windows/Mac). If the link speed is below 50 Mbps, you can
    • Move to a location with a stronger WiFi signal 
    • Switch to a different WiFi access point
  • Slow Internet speeds: It is important to check the WiFi link speed before checking the Internet speed. This is because slow WiFi will give inaccurate Internet speed results. Therefore, either check Internet speed from a device with a wired Ethernet connection or make sure your WiFi link is stable and fast before running the test. You can test Internet speed with a service such as Speedtest. If the speed test result indicates insufficient Internet bandwidth, you can 
    • Disable unnecessary services that consume Internet bandwidth, such as gaming, cloud backups, software downloads, video surveillance, etc.
    • Upgrade your Internet connection.
  • Browser: We have already discussed what you can do to resolve browser-related issues, such as closing unnecessary tabs, removing unwanted browser extensions and add-ons, and scanning for and removing malware. You can also
    • Update your browser to the latest version
    • Clear the temporary Internet files cache
    • Clear your browser cookies and cache
Techie Tip: With WiFi, you can use any device to work on, and you can work from any location with a good WiFi signal. However, WiFi is less reliable compared to a wired Ethernet connection. This is because the WiFi signal gets weaker the further you move away from the WiFi router/access point. WiFi is also susceptible to interference. Therefore, always use wired Ethernet for reliable connectivity between your computer/laptop and your Internet modem/router.

Malicious Software

Malicious software does not only affect your computer’s performance; it can also compromise your data and result in thousands of dollars in lost time and business.

There is a wide variety of malicious software, including:

  • Computer viruses that spread by making copies of themselves. 
  • Spyware that transmits personal information, such as credit card numbers.
  • Ransomware that gains access to a computer’s file system and encrypts all data. Shortly after a ransomware attack, the victim will receive a demand for ransom, which, if not paid, will result in the loss of all data.
  • Trojan Horses that advertise themselves as legitimate software and trick users into downloading and executing them. Once activated, a Trojan horse can harm the victim’s computer in several ways.
  • Scareware that tricks victims into thinking that their computers or mobile devices have been compromised.
  • And much more

Malware can get onto your computer in several ways, such as 

  • Clicking on an infected link or advert
  • Opening an email
  • Opening an attachment in a spam email
  • Software download from an untrusted website

If you suspect that your computer is affected by malware, you should use robust anti-virus software to scan your computer, isolate the malware, and then remove it. Alternatively, you can hire a malware removal service.

Removing malware after it has infected your computer is a necessity. However, a proactive approach to dealing with malware is a significantly better approach compared to a reactive approach: 

  • You cannot deal with an enemy that you don’t know or don’t understand. The most important aspect of proactive malware protection is to educate yourself about cybersecurity best practices.
  • Protect sensitive information such as usernames and passwords by not sharing them with anyone. Remember that banks never ask for your login information. Even if you get an email that looks legitimate, do not click on it, and do not share your confidential information.
  • Always use reliable antivirus software
    • Keep the software updated
    • Run regular virus scans on your computer
  • Keep your operating system and other apps updated so that your computer benefits from the latest security updates.
  • To minimize the risk of malware infections, only download apps, software, and media files from trusted sites, and avoid downloading files or apps from unfamiliar sites. 
  • Avoid clicking on unverified links in spam emails, messages, or suspicious-looking websites. 
  • Avoid using free Wi-Fi when using your computer in a public place. Use your mobile data connection if you have to go online. 
  • Avoid inserting unfamiliar USBs into your computer.

Outdated Hardware

If your computer is more than 8 years old, and you want to run the newest version of Adobe Photoshop on it, your computer will not be able to cope. It’s unlikely you’ll be able to install the software on your computer in the first place because modern software requires:

  • More processing power i.e. faster CPUs
  • More RAM to run smoothly, and 
  • More storage space i.e. free HDD capacity.

Microsoft launched Windows XP in 2001 and released Windows 11 in 2021. The table below shows the minimum hardware requirements for this software:

HardwareWindows XPWindows 11
CPU233 MHz1 GHz or faster
Free HDD space1.5 GB64 GB or more

There is a significant difference between the minimum hardware resources required to run this software. And the same holds true for other types of software such as games and multimedia design and editing solutions that are popular today.

Therefore, the only solution to the problem of outdated hardware is to replace it with new hardware. You can buy new components or replace your computer altogether. When you buy new components, you have to buy several at once to ensure all hardware is compatible with each other.


Computers run slowly from time to time. But a computer that runs slowly most of the time needs some investigating. 

As with every other type of problem, a systematic approach to computer performance troubleshooting will be far more successful than any ad-hoc approach.

First, you have to look at the symptoms:

  • Is the CPU overloaded?
  • Is the RAM fully utilized?
  • Is the hard drive out of storage space?
  • Are there any network-related issues?
  • Is the computer infected with a virus?
  • Is the computer more than 8 years old?

As it happens in life, problems don’t occur in isolation: often, one cause will manifest in multiple symptoms, such as a virus causing high CPU load and high RAM utilization.

Once you take a holistic view of the overall symptoms, you will have a good idea of what is causing the computer to run slowly. And then you can take appropriate steps to solve the problem.